Premiere for super­con­duct­ing diode with­out exter­nal mag­netic field

Trilayer graphene is a promising platform for the superconducting diode effect.
Credit: Mathias Scheurer

Superconductors are the key to lossless current flow. However, the realization of superconducting diodes has only recently become an important topic of fundamental research. An international research team involving the theoretical physicist Mathias Scheurer has now succeeded in reaching a milestone: the realization of a superconducting diode effect without an external magnetic field. They report on this in Nature Physics.

One speaks of a superconducting diode effect when a material behaves like a superconductor in one direction of current flow and like a resistor in the other. In contrast to a conventional diode, such a superconducting diode exhibits a completely vanishing resistance and thus no losses in the forward direction. This could form the basis for future lossless quantum electronics. Physicists first succeeded in creating the diode effect about two years ago, but with some fundamental limitations. "At that time, the effect was very weak and it was generated by an external magnetic field, which is very disadvantageous in potential technological applications," explains Mathias Scheurer from the Institute of Theoretical Physics at the University of Innsbruck. The new experiments carried out by experimental physicists at the renowned U.S. Brown University, described in the current issue of Nature Physics, does not require an external magnetic field. 

How hepatitis E outwits the immune system

Daniel Todt, Eike Steinmann and Toni Meister (from left) look at the image of a cell infected with the hepatitis E virus. The capsid protein can be seen in green, the cell nucleus in blue.
Credit: Department of Molecular and Medical Virology

Faulty virus particles could be a deception to distract the immune system from fighting infectious viruses.

Over three million people become infected with the hepatitis E virus every year. So far there is no specifically effective drug. An international research team has examined which factors are important for the virus in the course of its reproductive cycle and how it manages to maintain the infection. The researchers analyzed various mutations in the virus and found changes that may allow the virus to outsmart the immune system. The team from the Molecular and Medical Virology Department of the Ruhr University Bochum around Dr. Toni Meister, Dr. Daniel Todt and Prof. Dr. Eike Steinmann reports in the journal PNAS.

Advantages and disadvantages of mutations

An important defense mechanism against viral infections in our body are special proteins, the antibodies. These usually bind specifically to surface proteins of the virus in order to make it harmless. But viruses have developed strategies to avoid this identification. During infection with the hepatitis E virus, random mutations often result in virus variants that can coexist within an infected person. The antiviral agent ribavirin, which many chronically infected people receive, can even increase the formation of such viral variants.

Improved precision in biological age measurement

Schematic picture of how the reliability of the epigenetic clock (Y-axis: change in methylation) is improved in the new PC clock in longitudinal data (X-axis: year from baseline) from the research study "the Swedish Adoption Twin Study of Aging" (SATSA).
Credit: Sara Hägg 

Epigenetic clocks based on DNA methylation data are a type of biomarker that is useful for estimating biological age in population-based cohorts. However, usability has been limited by partially unreliable estimates due to this. noise in data. In a new study, we present a solution by introducing a method that reduces the noise in the epigenetic clocks for improved precision in longitudinal analyzes and clinical studies.

Biomarkers for aging can be obtained from cellular, molecular, functional and physiological measurements and used to study biological aging in humans. Many studies use the so-called "epigenetic clocks" based on DNA methylation data to analyze the relationship between biological aging and morbidity and mortality. Although these watches are currently considered to be the best predictors of biological age, they still include technical noise, leading to great variation in the measurements.

In order to make the clocks more useful for longitudinal analyzes and clinical studies, improved precision in the measurements is important. Here we present a method where principal component analysis (PCA) is used to separate noise from age-related signals. In this way, only biologically relevant signals are prioritized and the reliability of the PC watches is much higher compared to the original watches.

UF research shows a step toward restoring sea urchins: ‘The lawnmowers of reefs’

Sea urchin
Credit: Josh Patterson 

Coral reef ecosystems are severely threatened by pollution, disease, overharvesting and other factors. For thousands of years, long-spined sea urchins helped keep reefs intact. They eat seaweed, which can kill or seriously damage coral. Without coral, reefs suffer severe consequences, including diminished ability to support fish.

In the mid-1980s, more than 90% of the urchins that crawled the coral reefs in the western Atlantic and Caribbean died for reasons scientists have yet to determine. The population of the long-spined sea urchin – known scientifically as Diadema antillarum -- has been slow to recover on its own. That’s why scientists, including Josh Patterson, are stepping up their efforts to enhance urchin populations.

“You could call these urchins the lawn mowers of the reefs,” said Patterson, a UF/IFAS associate professor of fisheries and aquatic sciences. “They eat fleshy seaweeds that grow out of control on coral reefs and ultimately smother the corals.”

The UF/IFAS restoration ecologist is trying to return more of the urchin to an area that roughly includes the seas off the Florida Keys, Bermuda, the Yucatan Peninsula, Aruba and the Virgin Islands. He’s taken a small step toward the overarching goal of revitalizing the population of the vital echinoderm.

New Technology Sharpens Images of Black Holes

The emission from M87 has now been resolved into a bright, thin ring (orange colormap), arising from the infinite sequence of additional images of the emission region, and the more diffuse primary image, produced by the photons that come directly toward Earth (in blue contours). When viewed at the imaging resolution of the Event Horizon Telescope, the two components blur together. However, by separately searching for the thin ring, it is possible to sharpen the view of M87, isolating the fingerprint of strong gravity.
Credit: Broderick et al. 2022, ApJ, 935, 61

When scientists unveiled humanity’s historic first image of a black hole in 2019 — depicting a dark core encircled by a fiery aura of material falling toward it — they believed even richer imagery and insights were waiting to be teased out of the data.

Simulations predict that, obscured by that bright orange glow, there should exist a thin, bright ring of light created by photons flung around the back of the black hole by its intense gravity.

Now, a team of researchers has combined theoretical predictions and sophisticated imaging algorithms to “remaster” the original imagery of the supermassive black hole at the center of the galaxy M87*, first captured by the Event Horizon Telescope (EHT) in 2019. Their findings, published today in The Astrophysical Journal, are consistent with theoretical predictions and offer new ways to explore these mysterious objects, which are believed to reside at the hearts of most galaxies.

"The approach we took involved leveraging our theoretical understanding of how these black holes look to build a customized model for the EHT data," says Dominic Pesce, a study co-author based at the Center for Astrophysics | Harvard & Smithsonian and member of the EHT collaboration. "Our model decomposes the reconstructed image into the two pieces that we care most about, so that we can study both pieces individually rather than blended together."

Scientists Take Another Theoretical Step to Uncovering the Mystery of Dark Matter, Black Holes

A star (orange) that gets close to a supermassive black hole (black) can be tidally disrupted by the black hole’s strong gravitational pull. According to a new study, if ultra-light bosons exist (purple), they can affect the spin of the black hole, which in turn affects the rate at which tidal disruption events occur.
 Credit: Peizhi Du

Much of the matter in the universe remains unknown and undefined, yet theoretical physicists continue to gain clues to the properties of dark matter and black holes. A study by a team of scientists including three from Stony Brook University proposes a novel method to search for new particles not currently contained in the standard model of particle physics. Their method, published in Nature Communications, could shed light on the nature of dark matter.

The three Stony Brook authors include Rouven Essig, PhD, Professor in the C. N. Yang Institute for Theoretical Physics (YITP); Rosalba Perna, PhD, Professor in the Department of Physics and Astronomy, and Peizhi Du, PhD, postdoctoral researcher at the YITP.

Stars that pass close to the supermassive black holes located in the center of galaxies can be disrupted by tidal forces, leading to flares that are observed as bright transient events in sky surveys. The rate for these events to occur depends on the black hole spins, which in turn can be affected by ultra-light bosons (hypothetical particles with minute masses) due to superradiance. The research team performed a detailed analysis of these effects, and they discovered that searches for stellar tidal-disruptions have the potential to uncover the existence of ultra-light bosons.

A gold inflatable Martian House designed to withstand life on Mars has landed in Bristol

The exterior of the Martian House
Credit: Luke O’Donovan

A two-story house designed for future life on Mars has landed on M Shed Square in Bristol, UK as part of an ongoing public art project, Building a Martian House.

The brainchild of local artists and Watershed Pervasive Media Studio residents Ella Good and Nicki Kent, the project has been designed over several years and brought together space scientists, world renowned architects, engineers, designers, school children and the public, to explore how considering future life on Mars, a planet with low power, zero emissions and zero waste, can inspire us to think creatively about how we can live more sustainably on earth and reassess our relationship with consumerism.

A team led by Hugh Broughton Architects, world experts in creating buildings for extreme environments including the Halley VI British Antarctic Research Station, working in partnership with design studio Pearce+, developed the design of the house.

The design team worked alongside space science and engineering experts Professor Lucy Berthoud, Dr Robert Myhill and Professor James Norman from the University of Bristol. A cohort of construction companies led by Southern Construction Framework generously donated their time and expertise to bring the project to life and funding has been provided by the Edward Marshall Trust.

Male spiders maximize sperm transfer to counter female cannibalism

A male Nephila pilipes spider copulating with a female mate.
Resized Image using AI by SFLORG
Photo credit: Li Daiqin

When sexual conflict results in reproductive strategies that only benefit one of the sexes, it may result in evolutionary arms races. Male spiders have evolved behavioral mating strategies to improve their chances of mating despite the risk of being cannibalized by their mates.

Researchers from the National University of Singapore (NUS) have discovered that male spiders make choices on maximizing their mating success when they are at risk of being cannibalized by their female mates. Led by Associate Professor Li Daiqin from the NUS Department of Biological Sciences, the researchers found that a male chooses one of its paired sexual organs with more sperm for the first copulation with a cannibalistic female. Also, a male transfer significantly more sperm if a female is cannibalistic or when the female is of a much larger physical size.

The study was published in Communications Biology.

Increasing sperm transfer in the face of sexual cannibalism

The theory of the male mating syndrome posits that male spiders are under sexual conflict pressure in sexually cannibalistic situations, as they may only have a single chance to mate. In this study, the researchers explored whether male spiders use additional cannibalism countering strategies by focusing on two male mating tactics. One of which is the “better charged palp” hypothesis which predicts that male spiders selectively make use of one of its paired sexual organs, known as pedipalps or palps, containing more sperm for their first copulation. The other, referred to as the “fast sperm transfer” hypothesis, predicts accelerated insemination when the risk of female cannibalism is high.

Extreme events stress the oceans

Sea snails - the picture shows a pteropod - play an important role in the marine food web. They are especially sensitive to ocean warming and acidification.
Source: Universität Bern Credit: Charlotte Havermans

When marine heatwaves and ocean acidity extreme events co-occur, it can have severe impacts on marine ecosystems. Researchers at the Oeschger Center for Climate Change Research at the University of Bern have determined for the first time the frequency and drivers of these compound events and have projected them into the future.

It's not just the land that is groaning under the heat – the ocean is also suffering from heatwaves. In the Mediterranean Sea along the Italian and Spanish coasts, for example, water temperatures are currently up to 5 °C higher than the long-term average at this time of year. Scientists have investigated marine heatwaves for a few years now – for example at the University of Bern. However, relatively little is known about how marine heatwaves co-occur with other extreme events in the ocean. Such events are known as compound events and considered to be a major risk of climate change. While the processes that lead to extreme events on land, such as floods, forest fires, heatwaves, or droughts and how they interact with each other have been intensively studied in the past, the finding that ocean weather and climate extreme events can also occur in combination is relatively new.

A group of researchers at the Oeschger Center for Climate Change Research, led by Thomas Frölicher, has now investigated whether marine heatwaves co-occur in combination with extreme events in other potential marine ecosystem stressors. In addition to heat, potential stressors also include high acidity levels in the ocean. "For the first time, we have quantified the frequency of compound events in which marine heatwaves happen together with extreme acidity", says Friedrich Burger, postdoctoral researcher and first author of the study just published in the journal Nature Communications. Extreme events of high ocean acidity are occurrences where the proton concentration in seawater is higher than normal.

Detecting diabetes among people at risk

When diabetes starts to develop but no symptoms are yet detectable, part of the beta cells of the pancreas (in green) disappear (right image) compared to a healthy individual (left image). This previously undetectable decrease could be identified by measuring the level of 1,5-anhydroglucitol in the blood.
Credit: UNIGE - Laboratory of Prof. Pierre Maechler

A team from the UNIGE in collaboration with the HUG has discovered a molecule that can identify the development of diabetes before the first symptoms appear.

Diabetes is a severe and growing metabolic disorder. It already affects hundreds of thousands of people in Switzerland. A sedentary lifestyle and an excessively rich diet damage the beta cells of the pancreas, promoting the onset of this disease. If detected early enough, its progression could be reversed, but diagnostic tools that allow for early detection are lacking. A team from the University of Geneva (UNIGE) in collaboration with several other scientists, including teams from the HUG, has discovered that a low level of the sugar 1,5-anhydroglucitol in the blood is a sign of a loss in functional beta cells. This molecule, easily identified by a blood test, could be used to identify the development of diabetes in people at risk, before the situation becomes irreversible. These results can be found in the Journal of Clinical Endocrinology & Metabolism.

In Switzerland, almost 500,000 people suffer from diabetes. This serious metabolic disorder is constantly increasing due to the combined effect of a lack of physical activity and an unbalanced diet. If detected early enough at the pre-diabetes stage, progression to an established diabetes can be counteracted by adopting an appropriate lifestyle. Unfortunately, one third of patients already have cardiovascular, renal or neuronal complications at the time of diagnosis, which impacts their life expectancy.